His pious parents Ioann and Agafia of the Zalizo (lit. "Iron") family, named him Ivan (John) after John the Baptist. The lives of St. Sava, St. John of Damascus and “The Ladder” by St John Climacus were the models of virtuous life for the young Ivan. According to his biographer and disciple Dosyfej, while he was young in years he was perfect in wisdom, and the boy differed from other children by his high spiritual aspirations, with never a contradiction in his words, knowledge and actions.

At the age of 10 he secretly left home for the Transfiguration Ugornits Monastery (Preobrazhens’kyi Uhornyts’kyi) in the village of Pidhora, on the outskirts of the town of Terebovlya (Ternopil Oblast in western Ukraine), and asked the hegumen (abbot) to accept him “to serve the brothers”. When Ivan turned 12, he was tonsured as a monk and was given the name Job. Since then, he began to follow the example of the biblical Job as a model of living. Reaching the age of 31 (around 1581) he was offered priestlyordination, which he accepted.

After the repeated offers of a local Ukrainian Duke, Constantine Ostroz’kyi, the defender of Orthodoxy, he was transferred to the island monastery of the Exaltation of the Cross (Khrestovozdvyzhens’kyi) outside of Dubno that belonged to duke’s estates in the Rivne region of western Ukraine. The monastery was arranged after the canons of St. Theodore the Studite. There, for 20 years, Job served as hegumen (abbot) and engaged himself in the writing of theological books. The collection of his works, The Book of the Venerable Job of Pochayiv, Written by His Own Hand, contained 80 teachings, conversations, and sermons of St. Job, as well as excerpts he himself complied from the writings of the Holy Fathers. It was translated into Russian and republished in 1881 under the title Pchela Pochayevskaya (The Bee of Pochayiv), edited by the professor of the Kiev Theological Academy, N. Petrov.

Saint Job also critiqued Roman Catholic teachings regarding the use of unleavened bread in the Eucharist, among other doctrinal differences in the face of Roman Catholic persecution of Orthodoxy following the Union of Brest (1596). Many Orthodox Christians living in Poland at the time were deprived of their rights, and attempts were made to force them to convert to Catholicism. A number of Orthodox bishops even became apostates to Uniatism. To counteract this problem, St. Job and others defended Orthodoxy by copying and disseminating Orthodox books. Prince Ostroz’kyi was also responsible for the Ostrog Bible (1581), the first printed edition of the complete Orthodox Bible.

Job was quiet, brief in words, and the only sound heard from his lips was the Jesus prayer. For many days and weeks he would retreat into his locked cave, so narrow that entry is difficult, and so small that it was impossible to sit, stand or lie conveniently. From the long periods of kneeling, his knees were covered with wounds, and wearing knee-marks into the rock floor. His disciple Dosyfey recounts that he saw supernatural light coming from the depths of the cave, shining for two hours onto the opposite side of the church. Dosyfey records that at the sight was terrified and fell to the ground.

Job introduced strict discipline and other reforms of monastic life. During his time in office, the monastery had to fend off incessant attacks by Andrzej Firlej, Castellan of Belz, who sued the monks over his grandmother's bequest of extensive lands and a miracle-working icon of the Mother of God. In 1623, Firlej raided the monastery, taking the holy icon with him and keeping it until 1641, when a court decision finally restituted the icon to the monks.

In 1628 Job attended the Synod of Kiev, called to defend the Orthodox Church against Uniatism.

Sometime after 1642, he was tonsured into the Great Schema, and received the new monastic name of John.

After the first two visions, Metropolitan Dyonysij did not follow the order. Only after the third, when Job threatened him with misfortune should he continue to disobey, did Dyonysij see in it God’s will. The same day, the Metropolitan departed for Pochayiv and gave orders to open the grave of Job immediately.

This took place on 28 August 1659. His body was found to be incorrupt, emitting a wonderful and heavenly fragrance. The relics were taken to the Trinity Cathedral of the Lavra for veneration.

A second "Uncovering of the Relics" of St. Job of Pochayiv took place on 28 August 1833, at which his relics were solemnly transferred to a church consecrated to his honour which had been built at the Pochayiv Lavra.

Every year, on 28 August a great number of Orthodox pilgrims come to Pochayiv Lavra to honour Saint Job, venerate his relics, and ask for his intercession.

During the Zbarazh War of 1675, the cloister was besieged by the Turks, who reputedly fled upon seeing the apparition of the Theotokos (Mother of God) accompanied by angels and St Job. Numerous Turkish Muslims who witnessed the event during the siege converted to Christianity afterward. One of the monastery chapels commemorates this event.

The Battle of Pochaev during the Zbarazh War. The Theotokos and St. Job are depicted above the monastery, defending the cloister while the battle rages below.

In 1759, a coach of Count Mikołaj Bazyli Potocki capsized near the monastery walls. In a fit of anger, Potocki fired at his driver three times, all without avail. Attributing this failure to divine intervention, Potocki settled in Pochayiv and started to lavish gifts upon the cloister.

In 1773, Potocki (who was a Roman Catholic) petitioned the Pope to recognize the Pochayiv icon as miraculous and St Job as a Catholic saint. Only the former petition was satisfied.[citation needed]

On 28 October 1908 when the Bishop of Volhynia and the faithful celebrated the feast day of Saint Job, the Saint repeatedly appeared in a vision in front of the bishop and blessed the Holy Mysteries (Body and Blood of Christ).

The cave church of St Job contains a famous gift from Countess Orlova - a silver reliquary with relics of the saint.